Updated shader and fixed PNG output

apps/LoopThroughWithOpenGLCompositing/gl/PngScreenshotWriter.cpp

@@ -20,10 +20,10 @@ bool WritePngFile(
 	const std::filesystem::path& outputPath,
 	unsigned width,
 	unsigned height,
-	const std::vector<unsigned char>& rgbaPixels,
+	const std::vector<unsigned char>& bgraPixels,
 	std::string& error)
 {
-	if (width == 0 || height == 0 || rgbaPixels.size() < static_cast<std::size_t>(width) * height * 4)
+	if (width == 0 || height == 0 || bgraPixels.size() < static_cast<std::size_t>(width) * height * 4)
 	{
 		error = "Invalid screenshot dimensions or pixel buffer.";
 		return false;
@@ -83,19 +83,19 @@ bool WritePngFile(
 	if (SUCCEEDED(result))
 		result = frame->SetSize(width, height);
 
-	WICPixelFormatGUID pixelFormat = GUID_WICPixelFormat32bppRGBA;
+	WICPixelFormatGUID pixelFormat = GUID_WICPixelFormat32bppBGRA;
 	if (SUCCEEDED(result))
 		result = frame->SetPixelFormat(&pixelFormat);
-	if (SUCCEEDED(result) && pixelFormat != GUID_WICPixelFormat32bppRGBA)
+	if (SUCCEEDED(result) && pixelFormat != GUID_WICPixelFormat32bppBGRA)
 	{
-		error = "PNG encoder did not accept RGBA pixel format.";
+		error = "PNG encoder did not accept BGRA pixel format.";
 		result = E_FAIL;
 	}
 
 	const UINT stride = width * 4;
 	const UINT imageSize = stride * height;
 	if (SUCCEEDED(result))
-		result = frame->WritePixels(height, stride, imageSize, const_cast<BYTE*>(rgbaPixels.data()));
+		result = frame->WritePixels(height, stride, imageSize, const_cast<BYTE*>(bgraPixels.data()));
 	if (SUCCEEDED(result))
 		result = frame->Commit();
 	if (SUCCEEDED(result))
@@ -107,6 +107,8 @@ bool WritePngFile(
 	if (FAILED(result))
 	{
 		error = "Could not write screenshot PNG: " + HResultToString(result);
+		std::error_code ignored;
+		std::filesystem::remove(outputPath, ignored);
 		return false;
 	}
 
@@ -123,6 +125,9 @@ void WritePngFileAsync(
 	std::thread(
 		[outputPath, width, height, pixels = std::move(rgbaPixels)]() mutable
 		{
+			for (std::size_t index = 0; index + 3 < pixels.size(); index += 4)
+				std::swap(pixels[index], pixels[index + 2]);
+
 			std::string error;
 			if (!WritePngFile(outputPath, width, height, pixels, error))
 				OutputDebugStringA(("Screenshot write failed: " + error + "\n").c_str());
@@ -130,4 +135,3 @@ void WritePngFileAsync(
 				OutputDebugStringA(("Screenshot written: " + outputPath.string() + "\n").c_str());
 		}).detach();
 }
-

shaders/fisheye-equirectangular-mirror/shader.json

@@ -1,7 +1,7 @@
 {
   "id": "fisheye-equirectangular-mirror",
   "name": "Fisheye Equirectangular Mirror",
-  "description": "Unwraps a single fisheye lens into a 360x180 equirectangular map by mirroring the rear hemisphere into the same fisheye source.",
+  "description": "Unwraps a single width-filled 16:9 fisheye lens into a 360x180 equirectangular map by mirroring the rear hemisphere into the same fisheye source.",
   "category": "Projection",
   "entryPoint": "shadeVideo",
   "parameters": [
@@ -9,7 +9,7 @@
       "id": "lensFovDegrees",
       "label": "Lens FOV",
       "type": "float",
-      "default": 180.0,
+      "default": 190.0,
       "min": 1.0,
       "max": 220.0,
       "step": 0.1
@@ -27,7 +27,7 @@
       "id": "radius",
       "label": "Fisheye Radius",
       "type": "vec2",
-      "default": [0.5, 0.5],
+      "default": [0.5, 0.8889],
       "min": [0.001, 0.001],
       "max": [2.0, 2.0],
       "step": [0.001, 0.001]
@@ -59,15 +59,6 @@
       "max": 180.0,
       "step": 0.1
     },
-    {
-      "id": "seamAngleDegrees",
-      "label": "Seam Angle",
-      "type": "float",
-      "default": 0.0,
-      "min": -180.0,
-      "max": 180.0,
-      "step": 0.1
-    },
     {
       "id": "fisheyeModel",
       "label": "Fisheye Model",
@@ -80,6 +71,24 @@
         { "value": "orthographic", "label": "Orthographic" }
       ]
     },
+    {
+      "id": "edgeFill",
+      "label": "Edge Fill",
+      "type": "float",
+      "default": 0.06,
+      "min": 0.0,
+      "max": 0.3,
+      "step": 0.001
+    },
+    {
+      "id": "edgeBlur",
+      "label": "Edge Blur",
+      "type": "float",
+      "default": 0.018,
+      "min": 0.0,
+      "max": 0.12,
+      "step": 0.001
+    },
     {
       "id": "outsideColor",
       "label": "Outside Color",

shaders/fisheye-equirectangular-mirror/shader.slang

@@ -49,7 +49,7 @@ float normalizedFisheyeRadius(float theta, float halfFov)
 
 float3 equirectangularRay(float2 uv)
 {
-	float longitude = (uv.x - 0.5) * TWO_PI + radiansFromDegrees(seamAngleDegrees);
+	float longitude = (uv.x - 0.5) * TWO_PI;
 	float latitude = (0.5 - uv.y) * PI;
 	float latitudeCos = cos(latitude);
 
@@ -60,6 +60,39 @@ float3 equirectangularRay(float2 uv)
 	));
 }
 
+float sourceUvOutsideDistance(float2 uv)
+{
+	float2 lower = max(-uv, float2(0.0, 0.0));
+	float2 upper = max(uv - 1.0, float2(0.0, 0.0));
+	return max(max(lower.x, lower.y), max(upper.x, upper.y));
+}
+
+float4 sampleEdgeFilledVideo(float2 sourceUv, ShaderContext context)
+{
+	float outsideDistance = sourceUvOutsideDistance(sourceUv);
+	if (outsideDistance <= 0.0)
+		return sampleVideo(sourceUv);
+
+	float fillDistance = max(edgeFill, 0.0);
+	if (outsideDistance > fillDistance)
+		return outsideColor;
+
+	float2 clampedUv = saturate(sourceUv);
+	float2 inward = clampedUv - sourceUv;
+	float inwardLength = max(length(inward), 0.000001);
+	inward /= inwardLength;
+
+	float blurDistance = max(edgeBlur, 0.0);
+	float4 color = sampleVideo(clampedUv) * 0.32;
+	color += sampleVideo(saturate(clampedUv + inward * blurDistance * 0.35)) * 0.26;
+	color += sampleVideo(saturate(clampedUv + inward * blurDistance * 0.75)) * 0.20;
+	color += sampleVideo(saturate(clampedUv + inward * blurDistance * 1.20)) * 0.14;
+	color += sampleVideo(saturate(clampedUv + inward * blurDistance * 1.75)) * 0.08;
+
+	float edgeFade = smoothstep(fillDistance * 0.78, fillDistance, outsideDistance);
+	return lerp(color, outsideColor, edgeFade);
+}
+
 float4 shadeVideo(ShaderContext context)
 {
 	float3 ray = equirectangularRay(context.uv);
@@ -86,8 +119,9 @@ float4 shadeVideo(ShaderContext context)
 		center.y - sin(phi) * fisheyeRadius * radius.y
 	);
 
-	if (sourceUv.x < 0.0 || sourceUv.x > 1.0 || sourceUv.y < 0.0 || sourceUv.y > 1.0)
+	float2 guard = 0.5 / max(context.inputResolution, float2(1.0, 1.0));
+	if (edgeFill <= 0.0 && (sourceUv.x < -guard.x || sourceUv.x > 1.0 + guard.x || sourceUv.y < -guard.y || sourceUv.y > 1.0 + guard.y))
 		return outsideColor;
 
-	return sampleVideo(sourceUv);
+	return sampleEdgeFilledVideo(sourceUv, context);
 }